FCP frame loss problems :o

For some reason any time i place any kind of dissolve between two clips i start dropping frames. Right after the fade is over that scene in the viewer stutters. I am not sure what is going on. Im wondering if this is because i have had to import my clips via imovie. My camera is a sony using the avchd format. From there i would convert those files into an mp4 and then edit them through FCP. My specs of my mbp are listed in my profile. All help is appreciated.

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